Social Security Number (SSN), the nine-digit number, which is used widely by government agencies in the US, is often used as an example of an advance economy successfully doing something similar to India’s unique identity project. But there are important differences between the two, starting with the fact that the Social Security Number is, well, not an identity number.

The Social Security Number has its origins in the years of the Great Depression. During this period of economic recession in the US, the Roosevelt government launched the “New Deal”, a series of programmes to provide relief and employment to the poor.

In 1936, under the Social Security Act, it began using a nine-digit number, the Social Security Number, to track the earnings of workers and compute the amount of social security benefits to be credited to their accounts.

Over the years, the ease of using the number led more government agencies to incorporate it in their records. In 1961, for instance, the Internal Revenue Service began using the Social Security Number for taxpayer identification, similar to the Permanent Account Number in India.

With no legal restrictions on use of the Social Security Number by private companies, several businesses such as credit bureaus started asking individuals for their Social Security Number and storing it.

But in 1977, the Carter administration clarified that while it may used to be verify whether an individual had the legal permit to work, the Social Security Number could not serve as an identification document.

The Social Security Administration website states in a 2009 bulletin: “The card was never intended to serve as a personal identification document – that is, it does not establish that the person presenting the card is actually the person whose name and SSN appear on the card.”

By contrast, Aadhaar has been designed as a single, universal, digital identity number that any registered entity, whether public or private, can use to “authenticate” an Indian resident. Anyone who has lived in India for 182 days can enroll in Aadhaar for proof of identity, while only citizens and those authorised to work in the US can obtain a Social Security Number.

Aadhaar collects biometrics, which include the scan of all fingerprints, face and the iris of both eyes. Aadhaar Act’s section 2(g) states that “other biological attributes” may be collected in the future, a provision that was intensely debated in Parliament.

In contrast, when the Social Security Number was created in the 1930s, the US government decided not to collect fingerprints. “The use of fingerprints was associated in the public mind with criminal activity, making this approach undesirable,” notes the Social Security Administration website. The Social Security Number is thus printed on a small paper card and does not carry even a photograph.

In recent years too, the Social Security Administration has restrained from collecting biometrics of residents. In 2007, when the Intelligence Reform and Terrorism Prevention Act asked the SSA to improve the security of Social Security Number cards, the SSA considered adding the holder’s photograph or biometrics to the card but eventually decided against it.

“A biometric identifier, such as a fingerprint, can be an effective and highly accurate way to establish the identity of an individual, but it can also facilitate a much higher degree of tracking and profiling than would be appropriate for many transactions,” said Marc Rotenberg, the president of Electronic Privacy Information Center, a research organisation, in a testimony to the House of Representatives.

He added: “The problems that will arise when biometric identifiers are compromised are severe. What will happen at the point that your biometric identifiers no longer identify you?”

Around 2011, American authorities considered introducing a new biometrics-linked identity card for work authorisation for residents. Called the Biometric Enrollment, Locally-stored Information, and Electronic Verification of Employment or BELIEVE card, it aimed capture fingerprints or scans of veins on the back of hands.

BELIEVE card supporters presented it as necessary for immigration reform but many opposed it. “We pointed out that a biometrics ID system would be expensive, intrusive and ineffective, and requiring such an ID card would fundamentally transform the information demands the US government places on its citizens,” said Michael Froomkin, a professor of law at Miami University.